Lifting jack



W. H. GRIFFITH. 4

urmm JACK.

I I 7 APPLICATION FILED JULY M1920. v g gg Patented Nov. 2]., 1922..

Patented New. 21, 1922,

WILLIAM H. GRIFFITH, OF WOBTHINGTON, INDIANA.

LIFTINGr JACK.

Application filed July 8, 1920. Serial No. 394,735.

T 0 all whomit may concern Be it known that 1, WILLIAM H. GRIFFITH, acitizen of the United States, residing at Worthington, in the county ofGreene and State of Indiana, have invented certain new and usefulImprovements in Lifting Jacks, of which the following is aspecification.

My invention relates to an improvement in lifting-jacks.

The object of the present invention is to provide a quick-actinglifting-j ack, in which the mechanism may be slid either up or down onthe main bar or standard by properly manipulating the hand-lever, or toimpart a step by step motion at the desire of the operator, according tothe manner in which he controls the hand-lever.

Another object is to provide an improved means for letting the load downagain slowly by the manipulation or operation of the hand-lever.

The present invention consists in a pair of runners slidably mountedupon a bar or standard, and a hand-lever soconnected with the tworunners that in ordinary operation it will cause the runners toalternately climb and clutch the bar or standard, and by forcing thehand-lever first to one extreme position and then reversing it apredetermined distance, it will cause the release of both runners, andthe simultaneous lowering of both upon the bar or standard.

This invention further consists in a bar or standard, a pair of runnersslidably mounted thereon and constructed to automatically climb the baror standard, ahandlever connected with both runners, means connectedwith one runner and in position to be actuated by the hand-lever tocause one runner to be unclutched from the bar or standard, and meansconnected with the other runner in position to be actuated by thehand-lever to cause the release of said last-named runner from the baror standard, whereby both may be simultaneously lowered by the propermanipulation of th hand-lever.

In the accompanying drawings:-

Fig. 1 is a view from one side of the jack; Fig. 2 is a similar viewfrom the opposite side; and

Fig. 3 is an enlarged sectional view through the operative mechanism.

A, represents the main bar or standard,

the upier end of which is provided with a handle 1, and the lower end isremovably held in a base or. foot 52 by the pin, belt or key 3, whichmay be easily removed to take off the base or foot to assemble or removethe operative parts of the lifting-jack, all of which are slidablymounted on the main bar or standard.

The numeral 4 represents the main runner, which is made in the form ofacasting sleeved around. the main bar or standard and capable of slidingup and down thereon. This runner is hollow, and the holder 5 forclainoing the runner to the bar or standard is loosely housed. therein.and is normally held so that it clutches the front and rear edges of thebar or standard A, due to the action of the stiff spiral spring 6confined between the lower ed e of the holder at a point just in frontof the bar or standard and the bottom of the runner, as shown in Fig. 3.

One of the main f atures of my present invention is to absolutely bringthe control of this runner under the influence of the hand-lever, eitherto impart its step by step upward movement in the lifting operation, orin sliding the runner bodily either up or down. The means and mechanismwhereby this is accomplished, which constitutes a fulcrumed in a bearing9 formed for it in the forward end ot the runner 4. The handlever hasanother smaller stud 10. which en.- ters a bearing 11 in the bell-cranklever 12, which latter is fulcrumed on stud in the forward'end of thelower runner 13.

While the holder 5 within the. main runner might be rocked by hand, asheretofore, provision is made in my present invention for operating andcontrolling this holder entirely through the hand-lever; and for thispurpose the trip 14 is pivoted by means of a pin or rivet 15 in thelower forward end of the main runner preferably just forward of thebearing 9. This trip is approximately L-shaped, and is pivoted at ornear its center, so that the inner end extends over the nose 16 at theforward end of the holder 5,

1 neath, and oi" moving the upper end or the.

tially as fares it will go, upon the stud 8 as an axis, it has theeffect of swinging tne smaller stud 10 in the arc of a circletherebebell-crank lever 12 forward against the lower end of the tripwhich depends inimedt ately in its path, thus rocking the latter andcausing its inner end to press against the ends of the trip 1%, whichcauses the rear end of the holder 5 to swing dow' wardiy and carry withit al spring-actuated'dog 17 pivoted thereon. This enters a notch 18 inthe rear edge of the runner, thus unclutching the holder 5 from the baror standard 51, thus releasing the runners and permitting it to movefreely up and down.

Just so tar as the dog 17 is in the notch 18, the main runner l is freeto move in either direction, or in other words is unclutched from thebar or standard, and when the dog 17 is out oil? the notch 18 he holder5 automatically assumes aposition to clutch the forward and rear edgesof the bar or stand ard, due to the expansive action of the spring 6,which has been held under compression by the holder 5 when locked by thedog 1'? The action of the lower runner 13 is as follows: holder 5 isnorms held clutched to the bar or standard by the action of a spring 19interposed between the root of the runner 13 and the inner end of thebellcrank lever 12; but in order to bring this lower runner 13 under thecontrol of the handlever 7, when the runners are both to be lowered, theupstanding win 20 is cast integral witl'i its upper right-hand edge, anda spring-actuated plunger 21 is slidable in and out through the hole 22in the lower end of the hand-lever 7, in position to bear and slide backand forth against the outer sur face of the wing when the hand-lever isactuated in the operation of lilting theobject to be raised, duringwhich action the holder 5 and the lower runner 13 alternately clutch thebar or standard. 7

l'lUWCYEiT, is in The upper edge oi the win the form of acam 23, and byraising the hand-lever sufficiently far so that the plunger 21 clearsthe wing 20 and drops over the up per edge or cam surface 23, and thehandlever is then forced slightly downward, has the effect of forcingthe wing rearward, thereby suiiiciently tilting the lower runner 13 tohold it released from the bar or standard A. This is the action whichtakes place when the dog 17 is in the notch 18, and it is desired tosimultaneously lower both the. main runner 4i and the lower runner 13.The plunger is returned to its normal position over the surface of thewing by an incline or switch 24, over which it rides as the lever isforced down, and by which the plunger is. brought to the plane of theouter surface of the wing.

In the operation of raising the load, step-,-

by step, and-causing the main runner land the lower runner 3 to becomealternately clutched to the bar or standard ii, it is understood thatthe dog is is released from the notch 18, and the operator holds thehandlever in a relatively low position, almost horizonta giving butrelatively slight up and down motions. Then when it is desired to holdthe upper runner entirely released in the bar or standard A, by simplypre si the hand-lever down as far as it will go, it causes the trip isto tilt the holder until the dog 1'? entersthe notch 18 in the rear e geof the main runner a. This permits the main runner to more freely uponthe bar or standard it, when the holder 5 is thus locked to the runner,the .lC-T'Jef runner remains clutched to the bar standard 1, un theoperator desires to lower both runners, when he raises the hand-lever ur'il the plunger 21 clears the wing and tuAQS the position v the "ting itbacl: andfrocking the lows 13, thereby holding it released also from thebar or standard, which permits both runners to if" EildG to the bottomor until stopped by the operator. p

stud 25 on the inner side the hand lever Z is in position to strike thedog 17 and I release it from the notch 18 on the main run-- ne ifdesired, this being done by swinging -lever lnward, so that the studmoves incline 26 on the upper end oi the load to be lrrted by the stepby step action, due to the alternate clutching oi the main and lowerrunners upon the bar or stand as has been fully explained.

We accomplish the lifting, it is repeated. th hand-lever is v movedslightl up and down in a on not far horizontal. To again release theparts "he lever ac ie lens: is first pushed lo i as far nl go, whichcauses the dog to loci-z holder 5 in the main runner, thus releastherunner from the bar or standard, and

7 ii p i then by lifting the hand-lever until the slides over the top oithe wing,

plunger and then tly reversing it, it immediately slides all 01 themovable parts to the footer base, or as far down on the bar or standardas desired.

I claim:

1. In a lifting-jack, the combination with a bar or standard, of a pairof runners loosely mounted thereon, a hand-lever connected with bothrunners, and independent means connected with each'runner and actuate dby the hand-lever for releasing the runners from the bar or standardwhen the hand-lever is properly manipulated.

2. In a lifting-jack, the combination with a bar or standard, of a pairof runners ill) loosely mounted thereon, a hand-lever connected withboth runners, and independent means connected with each runner and actuated by the hand-lever for alternately releasing the runners from thebar or standard when the hand-lever is properly ma nipulated.

3. In a lifting-jack, the combination with a bar or standard, of a pairof runners loosely mounted thereon, a hand-lever connected with saidrunners, a holder connected with one runner and having a spring-ac--tuated dog pivoted thereto, and means comprising a pivoted trip carriedby said runner in position to be actuated by the handlever to swing theholder to a position where the dog locks the holder, thereby unclutchingthe runner from the bar or standard.

at. In a lifting-jack, the combination with a bar or standard and a pairof runners slidably mounted thereon, of a hand-lever connected with bothof said runners, a holder housed within one of the runners, and mountedloosely upon the bar or standard, a dog connected with the holder inposition to secure the holder unclutched from the bar or standard whenin a certain position, and a trip pivotally connected with the runner inposition to be actuated by the hand-lever, and when so actuated toengage the holder, and by moving it to unclutch it from the bar orstandard.

5. In a lifting-jack, the combination with a bar or standard and a pairof runners slidably mounted thereon, of a hand-lever connected with bothof said runners, a holder housed within one of the runners, and mountedloosely upon the bar or standard, a dog connected with the holder inposition to secure the holder unclutched from the bar or standard whenin a certain position, a trip pivotally connected with the runner inposition to be actuated by the hand-lever and when so actuated to engagethe holder and by moving it to unclutch it from the bar or standard,said dog having an incline thereon, and a hand-lever provided with astud in position to engage the incline and release the dog from therunner when desired to permit the holder to reclutch the bar orstandard.

6. In a littingjack, the combination with a bar or standard and tworunners slidably mounted thereon, of a hand-lever connected with saidrunners, a spring-actuated plunger slidably connected with thehand-lever, the lower runner having an upstanding wing with a cam switchon one edge, and the outer surface of the wing holding the plunger backin the hand-lever, and the plunger acting to force the wing back andtilt the runner when the plunger engages the cam edge thereof, theswitch being in position to return the plunger to its normal positionagainst the outer surface of the wing when the hand-lever is againdepressed.

7. In a lifting-jack, the combination with a bar or standard and runnersslidably mounted thereon, of a hand-lever pivoted directly to onerunner, a bell-orank lever pivoted to the other runner, and alsopivotally connected to the hand-lever, the lower runner having anupstanding wing thereon.

and the hand-lever provided with an inwardly-movable plunger, a holderwithin the main runner for normally clutching the latter to the bar orstandard, a trip pivoted to the main runner in the path of the bellcranklever in position to belrocked by the latter, and also in position toengage the holder to cause the latter to unclutch the runner, aspring-actuated dog pivoted to the holder and adapted to automaticallylock the latter in an unclutched position when tilted by the trip, dueto the movement of the hand-lever to a certain predetermined position,the other runner having an upstanding wing with a cam edge in positionto be engaged by the plunger on the hand-lever when raised to a certainposition for causing the lower runner to be rocked in position to cause.its release from the bar or standard, and the handlever having a stud inposition to release the dog on the holder from the main runner whendesired.

In testimony whereof I affix my signature.

WILLIAM H. GRIFFITH.

